Source to ddb/db_aout.c


Enter a symbol's name here to quickly find it.

/* 
 * Mach Operating System
 * Copyright (c) 1991,1990 Carnegie Mellon University
 * All Rights Reserved.
 * 
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 * 
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS 
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 * 
 * Carnegie Mellon requests users of this software to return to
 * 
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 * 
 * any improvements or extensions that they make and grant Carnegie the
 * rights to redistribute these changes.
 */
/*
 * HISTORY
 * $Log: db_aout.c,v $
 * Revision 1.1.1.1  1993/03/21 09:46:26  cgd
 * initial import of 386bsd-0.1 sources
 *
 * Revision 1.1  1992/03/25  21:44:55  pace
 * Initial revision
 *
 * Revision 2.3  91/02/05  17:05:55  mrt
 * 	Changed to new Mach copyright
 * 	[91/01/31  16:16:44  mrt]
 * 
 * Revision 2.2  90/08/27  21:48:35  dbg
 * 	Created.
 * 	[90/08/17            dbg]
 * 
 */
/*
 *	Author: David B. Golub, Carnegie Mellon University
 *	Date:	7/90
 */
/*
 * Symbol table routines for a.out format files.
 */

#include "param.h"
#include "proc.h"
#include <machine/db_machdep.h>		/* data types */
#include <ddb/db_sym.h>

#ifndef	DB_NO_AOUT

#define _AOUT_INCLUDE_
#include "nlist.h"

/*
 * An a.out symbol table as loaded into the kernel debugger:
 *
 * symtab	-> size of symbol entries, in bytes
 * sp		-> first symbol entry
 *		   ...
 * ep		-> last symbol entry + 1
 * strtab	== start of string table
 *		   size of string table in bytes,
 *		   including this word
 *		-> strings
 */

/*
 * Find pointers to the start and end of the symbol entries,
 * given a pointer to the start of the symbol table.
 */
#define	db_get_aout_symtab(symtab, sp, ep) \
	(sp = (struct nlist *)((symtab) + 1), \
	 ep = (struct nlist *)((char *)sp + *(symtab)))

#define SYMTAB_SPACE 63000
int db_symtabsize = SYMTAB_SPACE;
char db_symtab[SYMTAB_SPACE] = { 1 };

X_db_sym_init(symtab, esymtab, name)
	int *	symtab;		/* pointer to start of symbol table */
	char *	esymtab;	/* pointer to end of string table,
				   for checking - rounded up to integer
				   boundary */
	char *	name;
{
	register struct nlist	*sym_start, *sym_end;
	register struct nlist	*sp;
	register char *	strtab;
	register int	strlen;

	if (*symtab < 4) {
		printf ("DDB: no symbols\n");
		return;
	}

	db_get_aout_symtab(symtab, sym_start, sym_end);

	strtab = (char *)sym_end;
	strlen = *(int *)strtab;

#if 0
	if (strtab + ((strlen + sizeof(int) - 1) & ~(sizeof(int)-1))
	    != esymtab)
	{
	    db_printf("[ %s symbol table not valid ]\n", name);
	    return;
	}

	db_printf("[ preserving %#x bytes of %s symbol table ]\n",
		esymtab - (char *)symtab, name);
#endif

	for (sp = sym_start; sp < sym_end; sp++) {
	    register int strx;
	    strx = sp->n_un.n_strx;
	    if (strx != 0) {
		if (strx > strlen) {
		    db_printf("Bad string table index (%#x)\n", strx);
		    sp->n_un.n_name = 0;
		    continue;
		}
		sp->n_un.n_name = strtab + strx;
	    }
	}

	db_add_symbol_table(sym_start, sym_end, name, (char *)symtab);
}

db_sym_t
X_db_lookup(stab, symstr)
	db_symtab_t	*stab;
	char *		symstr;
{
	register struct nlist *sp, *ep;

	sp = (struct nlist *)stab->start;
	ep = (struct nlist *)stab->end;

	for (; sp < ep; sp++) {
	    if (sp->n_un.n_name == 0)
		continue;
	    if ((sp->n_type & N_STAB) == 0 &&
		sp->n_un.n_name != 0 &&
		db_eqname(sp->n_un.n_name, symstr, '_'))
	    {
		return ((db_sym_t)sp);
	    }
	}
	return ((db_sym_t)0);
}

db_sym_t
X_db_search_symbol(symtab, off, strategy, diffp)
	db_symtab_t *	symtab;
	register
	db_addr_t	off;
	db_strategy_t	strategy;
	db_expr_t	*diffp;		/* in/out */
{
	register unsigned int	diff = *diffp;
	register struct nlist	*symp = 0;
	register struct nlist	*sp, *ep;

	sp = (struct nlist *)symtab->start;
	ep = (struct nlist *)symtab->end;

	for (; sp < ep; sp++) {
	    if (sp->n_un.n_name == 0)
		continue;
	    if ((sp->n_type & N_STAB) != 0)
		continue;
	    if (off >= sp->n_value) {
		if (off - sp->n_value < diff) {
		    diff = off - sp->n_value;
		    symp = sp;
		    if (diff == 0)
			break;
		}
		else if (off - sp->n_value == diff) {
		    if (symp == 0)
			symp = sp;
		    else if ((symp->n_type & N_EXT) == 0 &&
				(sp->n_type & N_EXT) != 0)
			symp = sp;	/* pick the external symbol */
		}
	    }
	}
	if (symp == 0) {
	    *diffp = off;
	}
	else {
	    *diffp = diff;
	}
	return ((db_sym_t)symp);
}

/*
 * Return the name and value for a symbol.
 */
void
X_db_symbol_values(sym, namep, valuep)
	db_sym_t	sym;
	char		**namep;
	db_expr_t	*valuep;
{
	register struct nlist *sp;

	sp = (struct nlist *)sym;
	if (namep)
	    *namep = sp->n_un.n_name;
	if (valuep)
	    *valuep = sp->n_value;
}

boolean_t
X_db_line_at_pc()
{
	return (FALSE);
}

/*
 * Initialization routine for a.out files.
 */
kdb_init()
{
#if 0
	extern char	*esym;
	extern int	end;

	if (esym > (char *)&end) {
	    X_db_sym_init((int *)&end, esym, "mach");
	}
#endif

	X_db_sym_init (db_symtab, 0, "mach");
}

#if 0
/*
 * Read symbol table from file.
 * (should be somewhere else)
 */
#include <boot_ufs/file_io.h>
#include <vm/vm_kern.h>

read_symtab_from_file(fp, symtab_name)
	struct file	*fp;
	char *		symtab_name;
{
	vm_size_t	resid;
	kern_return_t	result;
	vm_offset_t	symoff;
	vm_size_t	symsize;
	vm_offset_t	stroff;
	vm_size_t	strsize;
	vm_size_t	table_size;
	vm_offset_t	symtab;

	if (!get_symtab(fp, &symoff, &symsize)) {
	    boot_printf("[ error %d reading %s file header ]\n",
			result, symtab_name);
	    return;
	}

	stroff = symoff + symsize;
	result = read_file(fp, (vm_offset_t)stroff,
			(vm_offset_t)&strsize, sizeof(strsize), &resid);
	if (result || resid) {
	    boot_printf("[ no valid symbol table present for %s ]\n",
		symtab_name);
		return;
	}

	table_size = sizeof(int) + symsize + strsize;
	table_size = (table_size + sizeof(int)-1) & ~(sizeof(int)-1);

	symtab = kmem_alloc_wired(kernel_map, table_size);

	*(int *)symtab = symsize;

	result = read_file(fp, symoff,
			symtab + sizeof(int), symsize, &resid);
	if (result || resid) {
	    boot_printf("[ error %d reading %s symbol table ]\n",
			result, symtab_name);
	    return;
	}

	result = read_file(fp, stroff,
			symtab + sizeof(int) + symsize, strsize, &resid);
	if (result || resid) {
	    boot_printf("[ error %d reading %s string table ]\n",
			result, symtab_name);
	    return;
	}

	X_db_sym_init((int *)symtab,
			(char *)(symtab + table_size),
			symtab_name);
	
}
#endif

#endif	/* DB_NO_AOUT */